1. Field of the Invention
The present invention relates to a flame retardant resin composition, a method for production thereof, and a molded article thereof, and particularly to a flame retardant resin composition comprising a cellulose resin, a method for production thereof, and a molded article thereof.
2. Description of the Related Art
Conventionally, petroleum resins such as a polyethylene resin, a polypropylene resin, vinyl chloride, polyamide, a polystyrene resin, and a PET (polyethylene terephthalate) resin, are widely used as a melt molding material including a material for injection molding and a material for extrusion.
Waste of daily necessaries and industrial products made from petroleum resins is recycled in part, but most of the waste is disposed by incineration, landfill and the like. Accordingly, cellulose resins attract attention as biomass resins to deal with global environmental problems such as global warming and running out of oil.
The cellulose resins are expected to be used for various purposes such as electrical and electronic equipment components, and materials for housing. When a resin composition comprising a cellulose resin is used for an exterior material of office automation equipment such as televisions and personal computers, the resin composition comprising a cellulose resin requires flame retardance, mechanical characteristics, and moldability.
Generally, in order for a resin as a polymer material to obtain flame retardance, a flame retardant is added to the polymer material. Representative examples of flame retardants include a halogen flame retardant, a phosphorous flame retardant, and an inorganic particle flame retardant. However, the halogen flame retardant has many problems on the environment such as the generation of halogen gas and black smoke at the time of combustion, and the generation of dioxin at the time of incineration. Furthermore, the phosphorous flame retardant has problems on the environment such as the generation of phosphine gas, and in addition, it has problems such as high prices and concerns about supplying mineral phosphate as a raw material.
On the other hand, magnesium hydroxide particles which are one of metal hydroxides representing inorganic particle flame retardants are harmless and have few problems on the environment. Furthermore, the magnesium hydroxide particles are inexpensive and can be derived from abundant raw material resources so that individual problems occurring in the halogen flame retardant or in the phosphorous flame retardant can be eliminated.
For a flame retardant comprising magnesium hydroxide particles, Japanese Patent Application Laid-Open No. 2007-119508 discloses the magnesium hydroxide particles which have a high flame retardance and a small amount of emission of carbon monoxide and smoke by including a transition metal compound at 100 to 1,000 ppm.
Japanese Patent Application Laid-Open No. 2000-086858 discloses a flame-retardant abrasion-resistant resin composition comprising a propylene-ethylene block copolymer, an ethylene-vinyl acetate copolymer, and a metal hydroxide represented by magnesium hydroxide, and further comprising a silane coupling agent having amino groups.
Japanese Patent Application Laid-Open No. 10-204298 discloses a flame retardant thermoplastic resin composition comprising a thermoplastic resin, a halogen flame retardant, a flame retardant agent, silicone, and magnesium hydroxide having particles with a particle diameter of 0.2 μm to 6 μm.
Japanese Patent Application Laid-Open No. 2006-232980 discloses a method for producing surface-coated flame retardant particles, comprising the steps of preparing a dispersion liquid of flame retardant particles with a particle diameter of 1 nm to 500 nm including magnesium hydrate in an aqueous solution in which metal salts of organic compounds and a dispersant are dissolved, and adding dropwise an acid aqueous solution into the dispersion liquid and depositing organic compounds on the surface of the flame retardant particles to form a coating layer.